This invention concerns information display devices of the kind in which a "writing" head carrying a set of actuators such as electromagnets is moved relative to a stationary matrix of correspondingly actuatable display elements, such as magnetically actuatable elements, so as to alter the appearance of selected elements, as disclosed, for example, in Salam U.S. Pat. No. 3,562,938.
It is an object of the present invention to facilitate the manufacture of matrix display devices having a large number of display elements, for example 500 rows by 2,000 columns, so as to be able to display more information and to show pictures in fine detail. In certain applications, it is desirable to have a high density of display elements, for example 50-100 per square inch, and the invention facilitates the manufacture of large matrices with such high densities.
Another object of the invention is to provide accurate registration between the actuating electromagnets and the display elements.